1. Field of the Invention
This invention is related to dentures and to an apparatus and method for locating lost dentures. This invention is also related to a signaling device that can be mounted in existing dentures or incorporated in new dentures and to a detector for locating the signaling device, attached to the lost denture within a certain area or an interrogation zone. The detector area or interrogation zone could be located at a building exit leading to a trash disposal collection area.
2. Description of the Prior Art
Medical institutions and long term care facilities in which patients and residents may suffer from diminished mental capacity or simple forgetfulness frequently have difficulty locating personal articles that have been misplaced or lost. One problem that is often encountered is that the patients or residents tend to lose or misplace their dentures. Patients or residents in such facilities often inadvertently throw their dentures in trash receptacles, leave them in pockets of clothing that is taken to a laundry facility or leave then on serving trays after meals. In rest homes and nursing care facilities, the resident may also place the dentures under sheets, in closets or in drawers where they can be difficult to locate. In some cases, the dentures are subsequently located by the institution""s personnel, who cannot identify the owner. In other situations the lost dentures are inadvertently disposed of in the trash or simply cannot be found within a reasonable time.
Although this problem occurs even when the institutions personnel are vigilant, it is especially upsetting to the residents and to their relatives. Lost dentures can be costly to replace, and relatives can be especially upset that the institution cannot keep track of their older relative""s dentures. In many cases, the institution must replace the dentures and is not reimbursed.
Medical institutions do encounter problems with lost articles in other contexts. For example, U.S. Pat. No. 5,923,001 discloses a surgical sponge detection system for use in an operating room in which detectable RF tags are attached to the sponges. U.S. Pat. No. 5,664,582 discloses a marker that can be used on a surgical instrument. However, these devices are used only within a controlled environment, and the problem of lost dentures arises because it is not possible to control the environment in which the loss may occur.
U.S. Pat. No. 4,160,971 discloses a passive transponder without a local power supply that is remotely powered by received transmissions. This device is primarily intended to measure pressure on dental plates. However, this device is intended to provide telemetry instead of a locator signal and it does not appear to be adapted for incorporation into denture that would be used for an extended period of time by an ordinary denture wearer. It also does not to be adapted for use with an existing denture.
Implants for use in a prosthesis are shown in U.S. Pat. No. 5,300,609 and in U.S. Pat. No. 5,855,909. However, these devices are also intended for data transmission instead of as a locator, and as such would not have the range to locate lost dentures.
A denture in accordance with the instant invention has base and teeth, including molar teeth, with a cylindrical glass encapsulated transponder embedded in the lingual flange of the denture adjacent molars mounted on the denture base. The transponder is covered by a denture material conforming to the contour of surrounding areas of the denture base, and the transponder emits a signal that can be remotely detected so that the denture can be found when lost.
The passive transponder can be mounted in a denture by forming a trench in a lingual area of a denture base adjacent molars on the dentures. The trench extends to a rear edge of the denture base. The transponder is then placed in the trench, and the trend is then filled to secure the transponder in the denture base.
This denture with a passive RF transponder can then be used in a system for locating a lost denture. The RF passive transponder contains an integrated circuit device connected to a coil. A reader having a transceiver for emitting an electromagnetic field is also used in the system. The electromagnetic field results in the generation of a voltage in the coil so that a code stored on the integrated circuit device is then transmitted through the coil to the transceiver for detecting the presence of a lost denture containing an RF passive transponder within a localized area.